In a rotary type image developing apparatus that has a rotary rack
accommodating a plurality of developer units and drives the rotary rack
to rotate in a predetermined rotational direction so as to bring a
targeted one of the developer units to a developing position, each
developer unit includes a toner storage in which a first slope is
disposed. As the rotary rack rotates, toner that remains upstream of a
toner supply opening in a toner flowing direction in the toner storage is
guided by a slope surface of the first slope, which enables the toner to
be smoothly supplied to a developing chamber. Thus, even when the toner
gets low, the toner can be efficiently supplied from the toner storage to
the developing chamber with the aid of the first slope.